Preparation method of single-crystal high-nickel positive electrode material, product and application thereof

Abstract

The invention relates to a preparation method of a single-crystal high-nickel positive electrode material, a product and application thereof. The preparation method comprises two steps of calcining. According to the first step of calcining, a nickel-cobalt precursor and / or a nickel-cobalt-manganese precursor are / is mixed with a lithium salt, and the obtained mixture is calcined, so that a single-crystal lithium nickel cobalt oxide material and / or a single-crystal lithium nickel cobalt manganese oxide material can be obtained. According to the second step of calcining, the product calcined in the step step is mixed with an aluminum source, and the mixture is calcined, so that the single-crystal high-nickel positive electrode material can be obtained. The temperature of the first-step calcining is higher than that of the second-step calcining. According to the method, a specific mixing sequence and a calcining method are combined, so that the generation of an impurity phase in the preparation process of the single-crystal high-nickel positive electrode material is reduced, the pure-phase single-crystal high-nickel positive electrode material is obtained, the performance of the single-crystal high-nickel positive electrode material is improved; and with the method adopted, the content distribution of an aluminum element in the single-crystal high-nickel positive electrode materialis easy to regulate and control, and the formation of an Al gradient material is facilitated, so that the capacity performance of the single-crystal high-nickel positive electrode material is improved.

Description

technical field [0001] The invention belongs to the field of battery materials, and relates to a preparation method of a single-crystal high-nickel positive electrode material, a product and a product application thereof. Background technique [0002] Since the first generation LiCoO 2 Since the commercial application of batteries, lithium-ion batteries have been widely used in 3C products, transportation, aerospace and military fields due to their advantages such as high energy density, long service life, no memory effect, wide operating temperature range, and environmental protection. With the rapid growth of demand for new energy vehicles, LiCoO 2 The energy density and cost of batteries have gradually failed to meet market requirements. As a new generation of lithium-ion battery cathode materials, nickel-cobalt-manganese (aluminum) oxide, a high-nickel ternary or quaternary material, is widely used in the field of electric vehicles due to its high specific capacity and...

AI Technical Summary

Problems solved by technology

However, when preparing single-crystal nickel-cobalt-lithium-aluminate or single-crystal nickel-cobalt-manganese-lithium-aluminate materials by increasing the calcination temperature (>800°C), Li 5 AlO 4 The impurity phase, causing the performance deterioration of the material

[0005] CN108987740A A method for preparing a nickel-cobalt lithium aluminate cathode material, comprising the following steps: preparing nickel-cobalt binary hydroxide; dispersing the nickel-cobalt binary hydroxide and soluble metal aluminum salt in a solvent, and adding Alkaline substances to adjust the pH of the solution to 8-13 to obtain a nickel-cobalt-aluminum precursor solution; adding an acidic substance to the nickel-cobalt-aluminum precursor solution to obtain a reaction solution of nickel-cobalt-aluminum hydroxide , when the pH value of the reaction solution is 7.5-10, stop adding the acidic substance; centrifuge, wash and dry to obtain nickel-cobalt-aluminum hydroxide; and mix the nickel-cobalt-aluminum hydroxide with Lithium salts are mixed, oxidized and calcined under pressure to obtain a nickel-cobalt-lithium-aluminate positive electrode material; CN105655579A discloses a nickel-cobalt-lithium-aluminate electrode material and its preparation method and application. The preparation method includes the following steps: a) , lithium source compound, nickel source compound, cobalt source compound, aluminum source compound, citric acid, diethylenetriaminepentaacetic acid and a solvent are mixed, and the pH value is adjusted to obtain a sol; b), the sol is aged to obtain a wet gel; c), the wet gel is sintered to obtain a nickel-cobalt-lithium-aluminate electrode material; the above scheme still has a high impurity content in the nickel-cobalt-lithium-aluminate material obtained during high-temperature calcination (>800°C), resulting in a The problem of deteriorating performance

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